Not being a lawyer and all that, I'd be surprised if any attempts to sue AFF for copyright breach would be considered. Organisations like Daily Mail and a host of others rip off content daily and pass it off as their own, and SFA happens to them. Reposting here is not in that category and the intent is to facilitate discussion. Any attempt to bring AFF to account would be met with subscription cancellations, you'd hope.
I think we are getting off-topic, but generally the issue isn't about who's right or who's wrong, rather it is the legal cost AFF will incur if they are forced to defend the case, so it's best for sites such as AFF to err on the side of caution and avoid the possibility of getting sued.